Too Much TV Could Shorten Your Lifespan

Our parents have always said too much TV will turn our brains to mush -- but now a new review of studies shows that it also raises the risk of Type 2 diabetes, heart disease and premature death.

Harvard researchers reviewed eight studies and found that for each two hours of TV watching a day, the risk of Type 2 diabetes goes up by 20 percent, the risk of heart disease goes up by 15 percent and the risk of premature death goes up by 13 percent.

That means for every two hours of TV watched a day among 100,000 people per year, 176 people will develop Type 2 diabetes, 38 people will develop heart disease and 104 people will die prematurely, according to the study, which was published this week in the Journal of the American Medical Association.

"The message is simple. Cutting back on TV watching can significantly reduce risk of type 2 diabetes, heart disease, and premature mortality," study researcher Frank Hu, professor of nutrition and epidemiology at Harvard School of Public Health, said in a statement. "We should not only promote increasing physical activity levels but also reduce sedentary behaviors, especially prolonged TV watching."

Researchers said the results of the study are likely because high amounts of TV time are closely linked with obesity. Obesity is in turn linked with bad eating habits, low physical activity levels and high risks of heart disease and Type 2 diabetes.

However, they acknowledged that limitations to the study include the small amount of studies reviewed, and that the amount of TV time reported by all the participants in the studies was self-reported and not independently observed. Researchers also said most of the studies didn't examine diet and levels of physical activity in conjunction with the study participants' TV time, the study said.